import java.util.Stack;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 晓星航
 * Date: 2023-03-16
 * Time: 19:10
 */
class MyQueue {

    public Stack<Integer> stack1;
    public Stack<Integer> stack2;
    public MyQueue() {
        stack1 = new Stack<>();
        stack2 = new Stack<>();
    }

    public void push(int x) {
        stack1.push(x);
    }

    public int pop() {
        if (empty()) {
            return -1;
        }
        if (stack2.empty()) {
            while (!stack1.isEmpty()) {
                stack2.push(stack1.pop());
            }
        }
        return stack2.pop();
    }

    public int peek() {
        if (empty()) {
            return -1;
        }
        if (stack2.empty()) {
            while (!stack1.isEmpty()) {
                stack2.push(stack1.pop());
            }
        }
        return stack2.peek();
    }

    public boolean empty() {
        return stack1.isEmpty() && stack2.isEmpty();
    }
}
public class MyQueueOJ {

}
